Examples

A doctor knows what he knows, and in our own age, his knowledge is increasingly specialized, which is to say narrow: he can treat ailments in certain parts of the body—which he does, day after day—but when it comes to other parts, he is altogether out of his depth; he performs certain procedures, but only them.

That era was characterized by certain specialized guilds in which afew skilled individuals dominated certain crafts like shoemaking and commanded large incomes while most of the inhabitants generally broke even finincially with a few exceptions.

This indicates that Mr. GUERRA had no subsequent training in specialized skills or abilities, and it specifically precludes any acquisition of martial arts skills, or assignment to duties or tasking as an INSTRUCTOR.